diff --git a/full_updater/backend/scanner.py b/full_updater/backend/scanner.py
index 27aee27..486b9fe 100644
--- a/full_updater/backend/scanner.py
+++ b/full_updater/backend/scanner.py
@@ -140,33 +140,41 @@ def scan_os(target: Target) -> str:
     """Récupère le nom, la version complète et le codename de l'OS."""
     prefix = [] if target.is_host else ["pct", "exec", target.target_id, "--"]
 
-    # 1. Lire /etc/os-release pour VERSION_ID (ex: 12.9) et PRETTY_NAME
+    # 1. Lire /etc/os-release
     ok, osrel_out, _ = run_cmd(prefix + ["cat", "/etc/os-release"], timeout=30)
     version_id = ""
     pretty_name = ""
+    codename = ""
     if ok:
-        ver_match = re.search(r'VERSION_ID="([^"]+)"', osrel_out)
-        if ver_match:
-            version_id = ver_match.group(1)
+        # Priorité 1 : DEBIAN_VERSION_FULL (ex: 13.4)
+        ver_full_match = re.search(r'DEBIAN_VERSION_FULL="?([^"\n]+)"?', osrel_out)
+        if ver_full_match:
+            version_id = ver_full_match.group(1).strip()
+        # Priorité 2 : VERSION (ex: "13 (trixie)")
+        if not version_id:
+            ver_match = re.search(r'VERSION="([^"]+)"', osrel_out)
+            if ver_match:
+                version_id = ver_match.group(1).strip()
+        # Priorité 3 : VERSION_ID (ex: "13")
+        if not version_id:
+            ver_match = re.search(r'VERSION_ID="([^"]+)"', osrel_out)
+            if ver_match:
+                version_id = ver_match.group(1).strip()
+        # Nom affichable
         pretty_match = re.search(r'PRETTY_NAME="([^"]+)"', osrel_out)
         if pretty_match:
-            pretty_name = pretty_match.group(1)
+            pretty_name = pretty_match.group(1).strip()
+        # Codename
+        code_match = re.search(r'VERSION_CODENAME="?([^"\n]+)"?', osrel_out)
+        if code_match:
+            codename = code_match.group(1).strip()
 
-    # 2. Récupérer le codename via lsb_release
-    ok, code_out, _ = run_cmd(prefix + ["lsb_release", "-cs"], timeout=30)
-    codename = code_out.strip() if ok else ""
-
-    # 3. Fallback sur /etc/debian_version si VERSION_ID vide
+    # 2. Fallback sur /etc/debian_version si tout vide
     if not version_id:
         ok, ver_out, _ = run_cmd(prefix + ["cat", "/etc/debian_version"], timeout=30)
         version_id = ver_out.strip() if ok else ""
 
-    # 4. Fallback sur lsb_release -rs
-    if not version_id:
-        ok, ver_out, _ = run_cmd(prefix + ["lsb_release", "-rs"], timeout=30)
-        version_id = ver_out.strip() if ok else ""
-
-    # 5. Récupérer le nom via lsb_release
+    # 3. Récupérer le nom via lsb_release
     ok, name_out, _ = run_cmd(prefix + ["lsb_release", "-is"], timeout=30)
     os_name = name_out.strip() if ok else ""